The front of vehicle is usually provided with a protection bar which prevents the front from slight collisions. A traditional protection bar 900 usually includes a frame 91 consisting of several tubes formed integrally and a fender 92 as shown in FIG. 1. When any part of the frame 91 is crushed, it is necessary to replace the whole protection bar 900 to guarantee its performance. Moreover, the protection bar 900 cannot be utilized on different vehicle models since the size, and in particular, the length of the frame 91, is fixed.